Trim-saw lift unit



Dec. 2, 1930 J. L. GOODSPEED TRIM SAW LIFT UNIT Filed Oct. 29, 1928 2Sheets-Sheet 1 INVENTOR J. L. GooDsPEED BY w? rru ATTORNEY Patented Dec.2; 1930 unrrnn stares arser oFFIcE JACK L. eoonsrEEn, or sEa'r'rLn,wAsnIneron, assieivon r0 rnrsoorr mow worms,

- or SEATTLE, WASHINGTON TRIM-sew LIFT un'rr be' trimmed as it isadvanced byaconveyer I mechanism across the trimmer table.

It is the principal object of this invention to provide a mechanicallyoperated 'device 'whereby a. saw may be lowered quickly to trimmingposition without undue jar and may likewise be raised clear of thelumber after 0 trimming has been 'done;the mechanism operatingautomatically at the completion of both the lowering and liftingmovements to disconnect the sawlitting and lowering memher from itsdriving element, so that-the saw will remain at either position ofadjustment until the operator, by'manipulation of acere tain controldevice, restores f tlie driving connection to again set the unit inoperation.

More specifically, the invention resides in the provision of a lift unitemploying in combination with a continuously driven gear, a yoke fromwhich the saw is suspended and which includes rack bars disposedatopposite sides of the gear and which, bylateral shitting of the yoke,may be selectivelyengaged with the gearto cause the yoke to be raised orlowered; the mechanism also including means for disconnecting the yoket'rom the gearat the completion of a lowering or rais-' ing adj ustment.e

Other obyects of the invention reside in the various details ofconstruction and in the com bination of parts and in their mode oioooration, as is hereinafter described.

I have provided the improved detailsot con: struction, the preferredforms of which are illustrated in Wherein r 7 Figure 1' is a sideelevation of a'trim saw lift unit embodying the present invention;

; the saw being shown in raised position.

. Figure 2 is an enlarged side. View oi the sawraising and loweringmechanism, shown Lin raised position. f

In accomplishing these and other objects,

the accompanying drawings,

Application filed. October 29, 1928. Serial No. 315,812..

Figure 3 is a similar view with the mechanism in lowered position. I

Figure iis a horizontal cross section taken substantially on the line Hin Figure 2.

Figure 5 is an enlarged detail view illustrating the relative, positionof the latch mechanism and control levers, when the unit is supported inraised position. 1

Figure ty'sa similar view showing relative position of parts when theyoke. is released for lowering the saw; Figure 7 is another view,illustrating the release of the yoke retaining latch for permittinglateral movement of the yoke preceding raising the saw.

l Referringmore in detail to thedrawing, In Figure 1,,1 designates thesupporting frame structure of a trimmer table having an upwardlyinclined top and having a revolubly driven shaitQ along itsupperedge'equipped with suitable sprocket wheels, as at 3, about whichconveyer: chains l'operate to advance theboards 5 beneath the trimmingsaws. Adja cent the table is a vertical frame structure comprising, inpart,a horizontal beam 6 to which a. plurality of saw ladders 7 arepivotally attached. In the present instance,th e ladder is swingingly pivotedat one end on a revolubly driven line shaft Stliat is supported from thebeam 6 so that the outer end of the ladder mayswing in a vertical planefrom and toward the trimmer table. At its outer end, the saw ladder isequipped with an arbor 9 whereon a circular saw 1O mounted; the

saw being. driven' byl-a sprocket chainbelt 11 operatlng about sultable'sprockets fixed, re-

spectively, on the arbor ,9 and on the shaft 8.

*In thepresent trimmer, the several saw ladders (only onebeing shown)are. each vertical movement in a guide andsupporting bracket that 1sfixedly mounted on the beam consi sts'ot all-shaped yoke 18 mounted for14;. In Figure 1, this bracket is designated in its entirety byreference numeral 19. A link 21 connects the lower end of the yoke withthe outer end of the saw ladder 7 so that the latter and the saw carriedthereby will be moved upwardly or downwardly in accordance with movementof the yoke.

The yoke 18 comprises the two parallel leg portions 18a and 187)connected across their lower ends by the cross piece 180 to which link21.is attached, and across their upper ends are connected by a plate 23that is at tached thereto by bolts 24; there being compression springs25 interposed between the ends of the plate and nuts 24s on the boltsfor absorbing shock incident to lowering.

The guide bracket 19, within which the yoke is slidably contained,comprises opposite side plates 19a and 197) that are disposed inparallel, spaced relation and provided with a-lined openings throughwhich the shaft 16 extends. At their outer ends, the side plates arerigidly joined to ether by transversely disposed bolts 28 and, at theirinner ends, they are rigidly joined by an integral top web 30 and a baseweb pro viding a vertical flange 32 which serves, with the horizontalweb 31, as a. seat whereby the bracketis mounted on the beam 1 1. Bolts33 are extended through the beam and through the flange 32 to secure thebracket in place.

Keyed on the shaft 16 between the side plates of the bracket 19, is agear pinion 35 which revolves continuously in the same direction, andthis is contained between the vertical rack bars 185! and 18?) of theyoke 18. The yoke is vertically slidable within a carrier which, inturn, is horizontally shiftable within the bracket 19 for the purpose ofshifting the yoke to bring one or the other of the rack bars intoengagement with the gear The carrier mentioned comprises opposite sideplates 3686 that are supported, respectively, just within the sideplates 19c and 19b of bracket 19; the supporting means consisting ofpins 87 and 38 which are extended through the ends of the plates andalso through horizontal slots 89 that are provided therefor in the sideplates of the bracket. These slots are of sufficient length as to permitof the necessary horizontal shifting of the carrier for bringing one orthe other of the rack bars into contact with the gear when this isdesired. The plates 36-36 are also provided centrally with elongatedslots 1O through which the shaft 16 extends and which also receivestherein the hub portions 11 of a pair of disks 42 that are disposedabout the shaft closely adjacent the opposite sides of the gear 35.These disks are circular and are of such diameter that they projectupwardly above the top of the bracket 17 and serve by direct contactwith the cross bar 23 as means for supporting the yoke 18 when in itslowered position.

Mounted on the pins 87 and 38, are rollers 45 which engage with theoutside, vertical edges of the yoke and serve as guides for the latteras it moves between raised and lowered positions. lVhen the yoke is inits raised position, it is supported by the end of a horizontallydisposed latch bolt 49 th t is slidably mounted between the side platesof the bracket upon one or more supporting elements 50. A roller 52,supported from the bracket, overlies the bolt to retain it in place onelements 50 and a coiled spring is fixed to a depending leg 49" at theouter end of the bolt and to a pin 54 fixed in the bracket side plate toyieldingly urge the bolt inwardly toward the yoke which is provided nearits lower end with an offset providing a downwardly facing shoulder 55for engaging the bolt as its means of support.

For drawing the bolt outwardly for releasing the yoke for downwardtravel, there is provided a lever 58 pivotally attached about midwaybetween its ends to the bracket by a pivot pin 59. This lever isattached at its lower end by a pin and slot connection, as at (30, withthe outer end of latch bolt 21-9 and, at its upper end, it projectssomewhat above the top of the bracket and has operative connection, asat 61, with the outer end of a horizontally extended lever 62 (see Fig.4) that is fixed to a pivot pin 63 mounted vertically in the bracket. Anactuating lever 64 is fixed to the pin 63 and to this a pull cable 65 isconnected. A coiled spring 66 attached, under tension, to the lower endof the lever 5S'and to the bracket to exert an inward pull on the lowerend of the lever.

Shifting of the carrier frame from right to left, as from the dottedline position to the full line position as shown in Figure 3. iseffected by the expansion of a coiled spring 70 that is retained undercompression between an abutment 71 at one end. of the carrier frame andan opposed abutment 72 at the outer end of the bracket. A. retaininglatch 75 is attached to the end of the carrier frame by a pivot pin 76and this has hook 77 at its end adapted to hook over a cross bar 78between the-bracket plates as a means of retaining the carrier frame atthe position as shown in Figure 2. Release of the latch to permitoutward shifting of the cari' .r, is effected by the lifting contactwith the hook of an inwardly extendin latch tooth 80 mounted in thecentral portion of the lever 58. This latch tooth has limited outwardtravel and is urged outwardly by a spring 81 housed back of the tooth.

For purposes presently apparent, it will be noted that the gear toothedsurfa e of the rack bar 1851 terminates at a spaced tance from the upperand lower end of the bar so that when the yoke is at either its up peror at its lower position of travel,the gear will revolve free of therack. It is also noted tends practically the length of the bar and atthe lower end oflthe' rack it curves inthen to move the yoke upwardlyand to therethat the toothed surface of'the bar 186 c wardly towardtherack bar 1864. The rack bars are so spaced "that the-gear can meshwith but one at a time. i

With the parts so constructed, and assembled .as described, theoperation of 'the device isv as follows:

Starting with the saw supported in raised position by the yoke 18 andlink 21, as shown in Figure 1, and with the latch-bolt 49 supporting theyoke, as shown in Figures 2 and 5, should it be desired to. lower thesaw, the

operator first pulls outwardly on the cable 65 and thereby, throughtheaction oflevers 64, 62 and 58, causes the latch bolt 49 to be drawnoutwardly and to be disengaged from supporting engagement with theshoulder of the yoke; When the latch bolt is-thus drawn out, the yoke ispermitted to drop of contact, when the crossbar engages the" disks, isabsorbed by the springs As the yoke reaches its lowered position thetoothed surface of the rack bar passes below the gear and the latterrevolves freely.

When it is desired to raise the saw, the oporator releases the pull onthe cable and the spring 66 operates to pull the lower end of the lever58 inwardly and by this movement.

brings the latch tooth 80 up against the lower end of thehook end 77 oflatch 75 and releases the hook from the cross piece 78,therebypermitting the spring 70 to expand and to T push the'carrier, inwhich the yoke is contained, outwardly so'that the yoke moves from thedotted line position of Figure 3 to the full line position. Thisshifting of the yoke brings the teeth of the rack bar 186 into mesh withthe gear 35 and the'gea-r operates by raise the saw. As the lower endportion of the rack bar 18?) reaches the gear 35, the

* inward curve of the rack surface causesthe yoke to be moved backtofthe right and final upward movement of the yoke brings vthe shoulder55 above the line of the lat-ch bolt a9 and the latter is snappedbeneath the shoulder by the inward pull of the spring'53, Simultaneouslywith the inward movement of the latch bar, the latch drops over thecross bar 7 8 andthus holds the carrier at the position shown in fulllines in Figure '2.

YVhen theyoke moves from its lowered to its raisedposition, the gear'35is automatical- 1y disconnected therefrom by running out of the lowerend of the rack bar 18?) and likewise,

when the yoke movies-from its raised to its lowered position, the gearis automatically disconnected from the rack 18a byrunning out from theupper 'end of the rack. Thus, the release ofthe driving connectionbetween the yoke and the gearis made automatic fonboth the raising andlowering movements.

Havingthus described my invention, what I claim as new therein anddesirefto secure by Letters Patent, is A 1. In a trim s walift unit",avertically-disposed saw suspendingfyoke comprising ver-' t1ca'l,'spacedracks, a driven gear disposed within the yoke, a releasable meansnormal-- ly supporting the yoke in raised position, Y

means for actuatingsaid supporting meansto release the yoke for downwardtravel andpermitone of'saidracks to engage the gear for a controlled"lowering of the'saw, meansfor limiting downward travel of the yoke afterthe gear has left the rack, manuallycontrolled means for shifting theyoke when in lowered position to engage the other of said racks 'withthe gear for raising the saw.

21h a trim saw lift un1t,a vertically. disposed saw suspending yokecomprising vertical, spaced racks, a driven gear dlsposed withinthe'yoke, a releasable means normallyf'supporting the yoke' in raisedposition, means for'actuating saidsupporting means to release the yokeand permit one of said racks to'engage the gearfor a controlled loweringof the saw, means for limiting'dowm ward 'tra'vel ofthe yoke afterthe'gear has left the rack-manually controlledmeans for shifting theyoke when in lowered position toengage the other of saidracks with thegear'forraising the sawand means for latera l ly shifting the yoke toeffect disconnecthe raising movement'ofthe yoke.

3; Ina trim saw lift un't, a fixedly mount ed bracket comprising spaced:apart side plates, a driven shaft extended transversely through thebracket, a gear keyed on the shaft --between the side plates, a yokecarrierhorizontally'adjustable within the bracket, asaw {suspending yokevertically slidable in t'he carrier between raised and lowered positionsfor raising and lowerin the saw; said yoke comprising vertlcal, spacedapart'racks' dis- -poseid at opposite sides; of said'gear, a latchbarengage'dwi'th the yoke for normally supporting it in raised position,1 means for shifting the bar to rele'ase-the yoke to" permit it to movedownwardly and to thereby engage one of the racks with the gear forlowering the saw, means for suppr' rting the yoke free of the gear whenit reaches its lower limit of travel, means for shifting the car rier tomove/the yoke to engage the other rack with the gear for raising thesaw: '7

tionjof thegear from-the racks. at the end of 4. In a trim saw liftunit, a fixedly mounted bracket comprising spaced apart side plates, adrivenshaft extended transversely through the bracket, a gear keyed 0nthe shaft between the side plates, a yoke carrier that is shiftahle.outwardly and inwardly within the bracket,

-with the gear for regulating the lowering of the saw, means forsupporting the yoke free of the gear when it reaches its lower limit oftravel, means for shifting the yoke carrier outwardly to thereby movethe yoke and to cause the other rack to engage the gear for raising theyoke; said latter rack being directed at its lower end toward theopposite rack for the purpose of returning the carrier to normalposition as the yoke again reaches its upper limit of travel.

5. A device as in claim 4, wherein a retaining latch is attached to thecarrier and engageable with a part fixed in the bracket for holding thecarrier in normal position inwardly of the bracket and a spring ismounted under compression between an abutment on the carrier and anabutment in the bracket for urging the carrier outwardly when saidlat-ch is released.

6. In a trim saw lift unit, a fixedly mounted bracket comprising spacedapart side plates, a driven shaft extended transversely through thebracket, a gear keyed on the shaft between the side plates, a yokecarrier shiftable outwardly and inwardly within the bracket, a sawsuspending yoke vertically slidable in the carrier between raised andlowered positions for raising and lowering the saw suspended thereby;said yoke comprising vertical, spaced apart racks disposed at oppositesides of said gear, a yieldable latch bar engaged with. the yoke forsupporting it when in its normal, raised position, a, pivoted releaselever for shifting the latch bar to release the yoke for downward travelto thereby engage one of the racks with the gear for lowering the saw,means for stopping and supporting the yoke free of the gear when itreaches its lower limit of travel, a latch attached to the carrier andengageable with a part fixed in the bracket for retaining the carrierinwardly of the bracket, a spring mounted under compression between anabutment on the carrier and an abutment in the bracket for urging thecarrier outwardly when said latch is released and a latch fingerprovided on said release lever engageable with the carrier latch torelease the latter.

7. In a trim saw lift unit, a fixedly mounted bracket comprising spacedapart side plates having horizontally alined slots therein, a yokecarrier mounted within the bracket, supporting pins for the carrierextended through said slots of the bracket and whereby inward andoutward movement of the carrier is limited, rollers mounted on said pinsat the ends of the carrier, a rotatably driven shaft extended throughthe bracket and carrier, the carrier having slots therein for receivingthe shaft, a gear keyed on the shaft within the carrier, a sawsuspending yoke mounted in the carrier between said rollers for verticaltravel between raised and lowered positions; said yoke comprising spacedapart racks, means for normally holding the yoke in raised position,means for releasing the yoke from said means to bring one of said racksurfaces into mesh with the gear for lowering the saw, means forshifting the carrier when the yoke is in lowered position to engage theother rack with the gear for raising the saw and means for returning thecarrier inwardly to normal position as the yoke reaches its raisedposition, and a releasable latch for normally retaining the carrier atits inner position.

Signed at Seattle, Washington, this 4th day of October, 1928.

JACK L. GOODSPEED.

